We recently discussed rapping on another thread. Today I found a light hearted article that overlays some serious technical ability. The article traces trends in rap based on a large data base of rap lyrics. Those denizens of the Agora who like at least some rap should enjoy the article. But even if you don't, consider applying the technology to tracking word usage from something like Google's database of books in print. Some of you guys have posted about similar stuff, but now it looks like sociologists might like to track trends in our countries in general. And the article shows how specific you can get.